This invention relates to improved sawmill methods and apparatus, and more particularly relates to improved methods and apparatus for cross-cutting the ends from sawlog slices to produce lumber, railroad ties and the like, cut to a predetermined length. More specifically, this invention further relates to a self-contained trimmer section for a fully automated sawmill.
It is well known that trees are grown and harvested to produce sawlogs, and it is also well known that these sawlogs are carried to sawmills where they are sliced into boards, timbers, railroad ties, and other forms of wood stock. In Applicants' U.S. Pat. No. 3,943,808, which issued Mar. 16, 1976, there is described and depicted a complete sawmill incorporating certain novel concepts including, but not limited to, a modular-type construction wherein each section of the mill is constructed so as to be structurally and functionally independent of the other sections, but wherein such sections can be quickly and easily joined together to produce a functionally integrated sawmill. As will hereinafter be explained in detail, a sawmill of this type is not only cheaper and easier to erect, it can also be disassembled and then re-erected at a different location. In addition, however, the operation of these sections can be easily integrated whereby automation of such a sawmill can be achieved.
Referring more particularly to the modular sawmill described in the aforementioned U.S. Pat. No. 3,943,808, it may be seen that a unique feature is a platform which is constructed of a plurality of scheduled piers, longerons and other prefabricated pieces to provide a unitary supporting structure having three functional levels. Thus, the modular sawmill may, after the platform has been erected, be assembled merely by depositing and by thereafter connecting the various sections together by means of appropriate electrical cables and pneumatic conduits, whereby the various sections are transformed into an integrated operating assembly as hereinbefore stated.
As also previously stated, since the various component sections of the mill are structurally independent of each other, they can be prefabricated and only thereafter carried to the millsite. Accordingly, most of the time required to erect such a sawmill will be spent in building the platform, since only a minimal period is required to position the modules or sections onto the platform and to thereafter cable them together into a functional unit.
As is more fully set forth in the aforementioned U.S. Pat. No. 3,943,808, the trimmer section of a sawmill conventionally performs its function intermediate of the originally slicing function and the disposition of the fully cut pieces to a location where they are held for loading onto trucks and the like. In an automated sawmill, therefore, the trimmer section performs an intermediate function which must be fully coordinated with functions performed both prior and subsequent thereto.
In accordance with the principles set forth for achieving the advantages of the modular concept, a trimmer section is hereinafter provided which automatically receives timbers and other partially cut pieces carried thereto, arranges and conducts such pieces to a location immediately preceding the trimming saws, selects and conducts each such piece individually to the trimming saws, cuts such pieces to a predetermined length or lengths, and thereafter discharges such trimmed pieces to other handling equipment which then transports them to one of a preselected holding locations.
In further consistency with the principles of a modular sawmill, the trimmer section incorporating the concepts of the present invention is structurally independent of the other sections of the sawmill, and is also adapted to be installed on the aforementioned platform for compatability with such other sections. On the other hand, and in further consistency with the aforementioned principles of the modular-type sawmill, the trimmer section embodying the present invention may either be operated independently of the other sections of the sawmill, or it may be functionally integrated with such components to produce a sawmill which is automated to a high degree.